condition mean min max ZT0-3 19.21125 19.21125 19.21125 ZT4-7 15.208450000000001 15.208450000000001 15.208450000000001 ZT8-11 17.879849999999998 17.879849999999998 17.879849999999998 ZT12-15 18.86505 18.86505 18.86505 ZT16-19 29.158549999999998 29.158549999999998 29.158549999999998 ZT20-23 22.981650000000002 22.981650000000002 22.981650000000002